If the letter is at the end of a word the symbol is drawn differently. However, it does not change the pronunciation or transliteration in any way. The name for the letter is final kaf (Kaf Sofit). Four additional Hebrew letters take final forms: tsadi, mem, nun, and pei. Kaf/khaf is the only Hebrew letter that can take a vowel in its word-final form which is pronounced after the consonant, that vowel being the qamatz.

In literary Arabic, kaf is used as a prefix meaning "like", "as", or "as though". For example, كَطَائِر (/katˤaːʔir/), meaning "like a bird" or "as though a bird" (as in Hebrew, above). The prefix كَـka is one of the Arabic words for "like" or "as" (the other, مِثْل/miθl/, is unrelated). The /ka/ prefix sometimes has been added to other words to create fixed constructions. For instance, it is prefixed to ﺫَلِك/ðaːlik/ "this, that" to form the fixed word كَذَلِك/kaðaːlik/ "like so, likewise."

Kaf is used as a possessive suffix for second-person singular nouns (feminine taking kāf-kasrahكِ, /ki/ and masculine kāf-fatḥahكَ/ka/); for instance, كِتَابkitāb ("book") becomes كِتَابُكَkitābuka ("your book", where the person spoken to is masculine) كِتَابُكِkitābuki ("your book", where the person spoken to is feminine). At the ends of sentences and often in conversation the final vowel is suppressed, and thus كِتَابُكkitābuk ("your book"). In several varieties of vernacular Arabic, however, the kaf with no harakat is the standard second-person possessive, with the literary Arabic harakah shifted to the letter before the kaf: thus masculine "your book" in these varieties is كِتَابَكkitābak and feminine "your book" كِتَابِكkitābik.

In addition, these variants are used distinctly in the Sindhi language as separate letters, to differentiate khē (using the simplified forms) from kāf (written in Sindhi with the long variant form shown in the subsection above).